Electronic Preprints
There are currently 2 electronic preprints awaiting publication. They are listed below in reverse chronological order.
2025
- Title
- Superconducting properties of thin film Nb1−xTixN studied via the NMR of implanted 8Li
- Author
- M. Asaduzzaman, R. M. L. McFadden, E. Thoeng, Y. Kalboussi, I. Curci, T. Proslier, S. R. Dunsiger, W. A. MacFarlane, G. D. Morris, R. Li, J. O. Ticknor, R. E. Laxdal, T. Junginger
- Abstract
-
We report measurements of the normal-state and superconducting properties of thin-film Nb1−xTixN using 8Li β-detected nuclear magnetic resonance (β-NMR). In these experiments, radioactive 8Li+ probes were implanted ∼21 nm below the surface of a Nb1−xTixN(91 nm) film in Nb0.75Ti0.25N(91 nm)/AlN(4 nm)/Nb and its NMR response recorded (via 8Li's β-emissions) between 4.6 K and 270 K in a 4.1 T field applied normal to its surface. Resonance measurements reveal wide, symmetric lineshapes at all temperatures, with significant additional broadening below the film's superconducting transition temperature Tc(0 T) = 15.4 ± 0.7 K due to vortex lattice formation. Fits to a broadening model find a magnetic penetration depth λ(0 K) = 180.57 ± 0.30 nm and upper critical field Bc2(0 K) = 18 ± 4 T, consistent with literature estimates. Spin-lattice relaxation (SLR) measurements find a Korringa response at low temperatures, with dynamic (i.e., thermally activated) contributions dominating above ∼100 K. Below Tc, we observe a small H bel-Slichter coherence peak characterized by a superconducting energy gap Δ(0 K) = 2.60 ± 0.12 meV and modest Dynes-like broadening. Our measurements suggest a gap ratio 2Δ(0 K)/kBTc(0 T) = 3.92 ± 0.25, consistent with strong-coupling behavior. Sources for the dynamic high-T relaxation are suggested.
- arXiv:2505.1459 [cond-mat.supr-con]
2020
- Title
- Digging into MUD with Python: mudpy, bdata, and bfit
- Author
- D. Fujimoto
- Abstract
-
Used to store the results of μSR measurements at TRIUMF, the Muon Data (MUD) file format serves as a useful and flexible scheme that is both lightweight and self-describing. The application programming interface (API) for these files is written in C and FORTRAN, languages not known for their ease of use. In contrast, Python is a language which emphasizes rapid prototyping and readability. This work describes three Python 3 packages to interface with MUD files and analyze their contents: mudpy, bdata, and bfit. The first enables easy access to the contents of any MUD file. The latter two are implemented specifically for the implanted-ion β-detected NMR (β-NMR) experiment at TRIUMF. These tools provide both an API and graphical user interface (GUI) to help users extract and fit β-NMR data.
- arXiv:2004.10395 [physics.data-an]